Over 150 million people are infected with Hepatitis C Virus (HCV) worldwide. Unfortunately, the current standard care, consisting of administration of a combination of interferon and ribavirin, is often unable to clear HCV infection in many infected individuals. Moreover, this treatment is associated with significant side effects, precluding its use by many individuals. Thus, current therapies are inadequate for the majority of the patients, and there is a pressing need for new drugs to treat HCV infection (See, Annals Internal Med. 132:296-305 (2000)).
The 9.6-kb positive single-stranded RNA HCV genome encodes a 3,000-amino-acid polyprotein that is proteolytically processed into structural proteins, which are components of the mature virus, and nonstructural proteins (NS), which are involved in replicating the viral genome (Curr Top Microbiol Immunol 242, 55-84 (2000)). Like other positive strand RNA viruses (B. N. Fields, D. M. Knipe, and P. M. Howley (ed.), Fields Virology. (Lippincott-Raven Publications, Philadelphia, Pa., 1996, in “The viruses and their replication”)), HCV appears to replicate in association with intracellular membrane structures. In the case of HCV, the structures are referred to as the membranous web (J Virol 76, 5974-5984 (2002)), the formation of which is believed to be induced by the NS4B protein. NS4B is also used to assemble the other viral NS proteins within the apparent sites of RNA replication (J Virol 78, 11393-11400 (2004)). It is not known how viral RNA, especially the negative strand template used for production of progeny genomes, might be incorporated or maintained at these replication sites.
There is an ongoing need in the art for agents that treat HCV infection; and for methods of identifying candidate agents that are suitable for treating HCV infection.